In the last few weeks, crews installed a version of the evil sea witch, Ursula, which at 7 1/2 feet tall and 12 feet wide is one of the largest animatronics ever created by WDI.

Located in the marquee scene of the dark ride, the Ursula figure can squash, stretch and bounce along to the music as she sings her big diva musical number, "Poor Unfortunate Souls."

Ursula's flexible rubber skin allows for a wide range of motions and emotions, said Ethan Reed, senior show animator for the Little Mermaid ride.

"She has analog eyelids so she can squint her eyes," Reed said. "You can really get some fun play in her eye area because that's where guests are going to look first."

In late February, crews installed more than 100 green, orange and yellow clamshell ride vehicles, which are similar to the Haunted Mansion "doombuggies." Most of the props and scenery inside the ride have been in place since January. Work is nearly complete on the building's exterior, inspired by the Dragon Gorge scenic railway at the long-gone Ocean Park amusement zone in Southern California.

An identical version of the ride, called Under the Sea: Journey of the Little Mermaid, is expected to open at the Magic Kingdom in Florida in 2013. The DCA ride will be officially titled The Little Mermaid: Ariel’s Undersea Adventure.